No Go Theorem for Self Tuning Solutions With Gauss-Bonnet Terms

TL;DR

This paper proves that in models with Gauss-Bonnet terms, self-tuning solutions for branes in anti-de Sitter space inevitably require fine tuning, challenging their viability for solving the cosmological constant problem.

Contribution

It introduces a new analysis method that clarifies why fine tuning is unavoidable in Gauss-Bonnet extended self-tuning brane models.

Findings

Self-tuning solutions with Gauss-Bonnet terms require fine tuning.

New qualitative analysis method simplifies understanding of solution properties.

Fine tuning origin is made transparent with the new approach.

Abstract

We consider self tuning solutions for a brane embedded in an anti de Sitter spacetime. We include the higher derivative Gauss-Bonnet terms in the action and study singularity free solutions with finite effective Newton's constant. Using the methods of Csaki et al, we prove that such solutions, when exist, always require a fine tuning among the brane parameters. We then present a new method of analysis in which the qualitative features of the solutions can be seen easily without obtaining the solutions explicitly. Also, the origin of the fine tuning is transparent in this method.